One step in the production of copper is to heat copper (I) sulfide, Cu2S, with oxygen. This produces copper (I) oxide and sulfur dioxide gas according to the following reaction: 2Cu2S(s) + 3O2(g) → 2Cu2O(s) + 2SO2(g)

What mass of SO2 can be produced from 15.0 mol Cu2S?

i think slash and

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.